Ladder tetrazine polymers

ABSTRACT

A ladder tetrazine polymer is disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims priorityfrom U.S. patent application Ser. No. 15/889,926 filed Feb. 6, 2018.

BACKGROUND Field of the Invention

The field of the invention is ladder polymers.

Description of Related Art

Renewable energy and materials is a rapidly growing field, thedevelopment of which is in higher demand than ever. One major branch ofrenewable energy is organic electronics and semiconducting materials.Organic semiconductors have several advantages over their silicon-basedcounterparts including renewability, their ability to besolution-processed into lightweight and flexible films, and theirability to have their properties easily tuned through chemicalsynthesis.

Important progress has been made towards making organic semiconductortechnology ubiquitous in everyday uses. Technologies such as organicphotovoltaics (OPVs) and organic batteries may provide a practical pathto achieve low-cost, renewable energy harvesting and storage. Plasticpolymeric power generation and storage sources offer intriguingopportunities for both portable solar cells and batteries, as suchmaterials are potentially flexible, lightweight, and easy to fabricatethrough low-cost processing techniques. Further, organic molecules mayoffer malleable properties that are easy to tune through chemicalsynthesis.

Functionalized fullerenes, such as phenyl-C61-butryic acid methyl ester(PCBM), have been the most commonly used n-type electron deficientmaterial in the active layer of OPVs. Although alternative n-typematerials have been investigated, such alternative materials have notbeen able to supplant PCBM as the n-type material to blend with p-typeconjugated polymers for OPVs. One of the drawbacks associated with PCBMis its weak absorbance in the visible and near-infrared regions of thesolar spectrum. Another problem with using PCBM in heterojunction OPVsis the difficulty associated with controlling the morphology of theresulting films. In heterojunction-based OPVs, it is desirable to haveinterpenetrating regions of the polymer and PCBM for an orderedheterojunction active layer in an OPV device. As PCBM is a smallmolecule, blending the two materials and spin-casting the materials ontothe desired substrate may result in a bulk-heterojunction (BHJ) OPV with“islands” of PCBM (and/or “islands” of p-type material). These “islands”are dead zones for charge-separated holes and electrons as they will notbe able to reach the electrodes at either end of the solar cell. Thus,there is a need to create an alternative n-type material to PCBM.

In addition to creating a PCBM alternative, it is desirable to designmaterials with low band gaps. Low band gap materials based on fused,aromatic organic compounds are important to the development of organicphotovoltaics (OPVs) as they can absorb the longer wavelengths of thesolar spectrum that smaller aromatic units cannot (such as PCBM). Bandgaps can be reduced by increasing the planarity of the conjugatedbackbone by minimizing various steric interactions between aromaticunits. Steric interactions tend to cause backbone twisting that resultsin a pi-electron conjugation that is only effective over shorter,segmented distances. This distance is affected by the structure ofdifferent compounds and inherently varies between different materials.As the conjugation length is increased, the band gap will decreasecontinually. However, conjugated organic materials will reach a point atwhich additional conjugated units will no longer result in significantband gap decrease. In this way, increasing conjugation length quicklyapproaches an asymptotic value for the band gap.

One approach to synthesize highly planar, low band gap materials is byusing polymeric systems that are fused through the majority of, if notthe entirety of, a conjugated polymer (CP). A CP that is comprisedentirely of fused rings is called a ladder polymer. Due to the reasonsmentioned above, ladder polymers generally have very low band gaps.Further, an additional benefit of an extended fused ring system isbetter charge transport due to pi-stacking between adjacent polymerchains. One challenge associated with ladder polymers is poor solubilityin organic solvents to remain solution processable.

SUMMARY

According to an embodiment, a ladder tetrazine polymer is disclosed.

According to another embodiment, an organic photovoltaic (OPV) device isdisclosed. The OPV device has an active layer than includes a laddertetrazine polymer.

According to another embodiment, a process of forming a ladder tetrazinepolymer is disclosed. The process includes forming a tetrazine-phenylenecopolymer from a tetrazine monomer and a phenyl monomer. The processalso includes forming a ladder tetrazine polymer from thetetrazine-phenylene copolymer.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescriptions of exemplary embodiments of the invention as illustrated inthe accompanying drawings wherein like reference numbers generallyrepresent like parts of exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chemical reaction diagram illustrating the formation ofladder tetrazine polymers from a tetrazine-phenylene copolymer,according to one embodiment.

FIG. 2 is a chemical reaction diagram illustrating a process of formingthe tetrazine-phenylene copolymer of FIG. 1 from a phenyl monomer and atetrazine monomer, according to one embodiment.

FIG. 3 is a chemical reaction diagram illustrating a process of formingthe phenyl monomer and the tetrazine monomer of FIG. 2, according to oneembodiment.

FIG. 4 is a chemical reaction diagram illustrating a process of formingthe tetrazine-phenylene copolymer of FIG. 1 from a phenyl monomer and atetrazine monomer, according to one embodiment.

FIG. 5 is a chemical reaction diagram illustrating a process of formingthe phenyl monomer of FIG. 4, according to one embodiment.

FIG. 6 is a flow diagram showing a particular embodiment of a process offorming a ladder tetrazine polymer from a tetrazine-phenylene copolymer.

FIG. 7 is a flow diagram showing a particular embodiment of a process offorming an active layer of an organic photovoltaic (OPV) device from ablend that includes a ladder tetrazine polymer.

DETAILED DESCRIPTION

The present disclosure describes ladder tetrazine polymers and methodsof forming ladder tetrazine polymers. In a particular embodiment, theladder tetrazine polymers of the present disclosure may be used as acomponent of an active layer of an organic photovoltaic (OPV) device. Asan example, the ladder tetrazine polymers of the present disclosure maybe used as an alternative n-type material to PCBM in the active layer ofthe OPV device. As another example, the ladder tetrazine polymers of thepresent disclosure may be an active component of an organic battery.

As described further herein, the ladder tetrazine polymers of thepresent disclosure may have desirable solubility characteristics,allowing for processing by common polar solvents, such as chloroform,THF, DMF, chlorobenzene, and dichlorobenzone (or non-polar solvents,such as toluene). Further, the high ionic content of the laddertetrazine polymers of the present disclosure may allow for aqueousprocessing. Tetrazine moieties allow for four ladder linkages permolecule as well as more imines per repeat unit. The enhanced number ofimines allows for a more electron deficient polymer, resulting in anarrower band gap that is ideal for n-type materials.

Referring to FIG. 1, a chemical reaction diagram 100 illustrates anexample of the formation of ladder tetrazine polymers from atetrazine-phenylene copolymer, according to an embodiment. In FIG. 1,two example ladder tetrazine polymers are illustrated (identified as“Ladder Tetrazine Polymer(1)” and “Ladder Tetrazine Polymer(2)” in FIG.1). As illustrated and further described herein with respect to FIG. 2and FIG. 4, the tetrazine-phenylene copolymer of FIG. 1 may be formedvia co-polymerization of a phenyl monomer and a tetrazine monomer viaSuzuki cross-coupling conditions.

The first example ladder tetrazine polymer depicted at the top of FIG. 1may be formed by thionyl chloride-promoted cyclization. As shown in FIG.1, the TBS-protected hydroxyls are reacted with thionyl chloride whichallows the imines of the tetrazine ring to cyclize via intramolecularnucleophilic substitution on the resulting chlorides. The final stepcreates the ladder tetrazine polymer with four quaternized iminiumcations per polymer chain. Not only can this polymer be processed bycommon polar solvents for organic conjugated polymers (CPs) likechloroform, tetrahydrofuran (THF), and dimethylformamide (DMF), but itshigh ionic content may allow for aqueous processing.

Prophetic Example: Formation of Ladder Tetrazine Polymer(1)

To a solution of the poly(tetrazine-phenylene) in an organic solventwhich may include acetonitrile, chloroform, chlorobenzene, etc. may beadded thionyl chloride, and the reaction mixture may be stirred at roomtemperature for 24 hours. The solvents may be removed in vacuo, and theresulting solid residue may be washed with solvents which may includemethanol and DMF.

If difficulty is encountered attempting to dissolve the final polymer incertain organic solvents, a modified ladder polymer forming reaction(shown at the bottom of FIG. 1) can be used that involvestetrabutylammonium fluoride (TBAF) and RSO₂F (where R is an alkylchain), which results in an ionic polymer with increased solubility (dueto the alkyl-functionalized anions). R may be branched or linear alkylchains (e.g., C1-C20). In the case of branched alkyl chains, a typicalbranching point may be at either C1 or C2, while other examples such as3,7-dimethyloctyl chains have alternate branching points.

Prophetic Example: Formation of Ladder Tetrazine Polymer(2)

To a solution of the poly(tetrazine-phenylene) in an organic solventwhich may include acetonitrile, chloroform, chlorobenzene, etc. may beadded an alkylsulfite fluoride and a 1 M solution of TBAF in THF, andthe reaction mixture may be stirred at reflux for 24 hours. The reactionmay be cooled to room temperature and may be precipitated into hexane.The precipitate may be collected by filtration or centrifugation anddried. The obtained solid may be purified by any combination of Soxhletextraction, successive precipitation, or column chromatography.

In a particular embodiment, as described further herein, the laddertetrazine polymer(s) of FIG. 1 may be used as an n-type component in OPVdevices, such as a replacement for fullerenes including PCBM. As anotherexample, the ladder tetrazine polymer(s) of FIG. 1 may be used as theactive component in an organic battery. The ability of the laddertetrazine polymers of FIG. 1 to be processed with organic semiconductormaterials in organic solutions as bulk-heterojunction blends as well asin aqueous solutions for orthogonal processing in layered devices isadvantageous.

Thus, FIG. 1 illustrates an example of a process of forming laddertetrazine polymers from a tetrazine-phenylene copolymer. The laddertetrazine polymers depicted in FIG. 1 have desirable solubilitycharacteristics, allowing for processing by common polar solvents, suchas chloroform, THF, DMF, chlorobenzene, and dichlorobenzone. Further,the high ionic content of the ladder tetrazine polymers may allow foraqueous processing. The tetrazine moieties allow for four ladderlinkages per molecule as well as more imines per repeat unit, whichallows for a more electron deficient polymer, resulting in a narrowerband gap that is ideal for n-type materials.

Referring to FIG. 2, a chemical reaction diagram 200 illustrates anexample of a process of forming the tetrazine-phenylene copolymerdepicted in FIG. 1. FIG. 2 depicts a first example of a phenyl monomer(e.g., a dibrominated phenyl monomer) and a tetrazine monomer (e.g., atetrazine boronic ester monomer) that may be co-polymerized via Suzukicross-coupling conditions. As illustrated and further described hereinwith respect to FIG. 4, alternative phenyl/tetrazine monomers may beused to form the tetrazine-phenylene copolymer. The example phenyl andtetrazine monomers depicted in FIG. 2 may be synthesized according tothe reaction schemes illustrated and further described herein withrespect to FIG. 3.

The phenyl monomer and tetrazine monomer are polymerized under Suzukicross-coupling conditions to yield a tetrazine-phenylene copolymer. Anillustrative example of Suzuki cross-coupling conditions includes theuse of Pd(PPh₃)₄ as the Pd catalyst, Cs₂CO₃, and water ordimethoxyethane (DME) as a solvent.

Prophetic Example: Formation of Tetrazine-Phenylene Copolymer

A reaction vessel may be charged with the dibromide (1 equiv.), and thediboronic ester (1.05 equiv.), palladium catalyst (1-5 mol %) such aspalladium acetate(II) or palladium tetrakis(triphenylphosphine), and aligand such as tri(o-tolyl)phospine (3-10 mol %). The atmosphere of thereaction vessel may be displaced with an inert gas such as nitrogen orargon. A degassed solvent mixture such dimethyl ether and aqueoussolution of an alkaline base such as cesium carbonate (>2 equiv., 2.0 M)may be added to the reaction vessel. A phase transfer agent such asaliquat 336 may be added to the reaction mixture, and the reactionmixture may be stirred at reflux for an extended period of time untilthe reaction is complete. After the reaction, the polymer may beprecipitated by pouring into a solvent such as methanol, acetone, orhexane, and may be filtered. The obtained solid may be purified by anycombination of Soxhlet extraction, successive precipitation, or columnchromatography.

Thus, FIG. 2 illustrates an example of a process of forming atetrazine-phenylene copolymer for use in forming the ladder tetrazinepolymers of the present disclosure. The tetrazine moieties allow forfour ladder linkages per molecule as well as more imines per repeatunit, which allows for a more electron deficient polymer, resulting in anarrower band gap that is ideal for n-type materials.

Referring to FIG. 3, a chemical reaction diagram 300 illustrates anexample of a process of forming the phenyl monomer and the tetrazinemonomer depicted in FIG. 2. In the first set of chemical reactionsdepicted at the top of FIG. 3, the phenyl monomer is synthesized fromdurene via a number of simple, high-yielding steps, resulting in a finalmolecule functionalized with para-arylbromides for step-growthpolymerization as well as silyl-protected hydroxyl groups which are usedto form the ladder tetrazine polymer after copolymerization with atetrazine monomer. In the second set of chemical reactions depicted atthe bottom of FIG. 3, the tetrazine monomer is synthesized by apalladium-catalyzed borolyation reaction of either dichlorotetrazine ordibromotetrazine.

With respect to the phenyl monomer, the first set of chemical reactionsillustrates the dibromination of commercially available1,2,4,5-tetramethyl benzene (also referred to as durene). Next,1,2,4,5-tetravinylbenzene is synthesized by radical bromination of thefour benzyl positions of 1,4-dibromo-2,3,5,6-tetramethylbenzene,followed by Wittig reaction conditions with paraformaldehyde. This isthen subjected to hydroboration conditions to make a tetra-ethanoldibromobenzene. Each hydroxyl group is then protected bytert-butyldimethylsilyl (TBS) protecting groups.

Prophetic Example: Preparation of Phenyl Monomer

Dibromination of 1,2,4,5-tetramethyl benzene (also referred to asdurene): The reagent 1,2,4,5-tetramethylbenzene (1.0 equiv.) may bedissolved in dichloromethane. To this stirred solution may be addedIodine (2.0 mol %) followed by a slow dropwise addition of a solution ofBromine (2.6 equiv.) in dichloromethane. After the addition is complete,the resulting solution may be heated to boiling for 1.5 hours. Uponcooling, 5M aq. NaOH may be added to the reaction mixture to neutralizethe residual bromine. The product may be collected by filtration, washedwith water and dried to furnish 1,4-dibromo-2,3,5,6-tetramethylbenzene.

Synthesis of 1,2,4,5-tetravinylbenzene:1,4-dibromo-2,3,5,6-tetramethylbenzene (1.0 equiv.), N-Bromosuccinimide(>4.0 equiv.) may be added to a stirred solution of AIBN (0.01-0.02 mol%) in DCM, Chloroform, or carbon tetrachloride at room temperature. Thereaction mixture may be heated to reflux and stirred for 5 h, at whichtime the product has precipitated. The reaction mixture may be allowedto cool to room temperature, and the product may be filtered and washedwith cold dichloromethane (5×100 mL). The white solid may be dried undervacuum. The resulting white solid is used in the subsequent reactionwithout further purification. A solution of the product from theprevious step (1.0 equiv.) and triphenylphosphine (2.5 equiv.) indimethylformamide may be heated at reflux for 18 h. The solvent may beremoved, and the residue may be dissolved in tetrahydrofuran, and anexcess of paraformaldehyde may be added. Potassium tert-butoxide (3.0equiv.) in tetrahydrofuran is then transferred in the reaction vessel.The solvent is evaporated, and the residue may be purified on a silicagel column with hexane as the eluent. Removal of solvent andrecrystallization from absolute ethanol may also be used.

Synthesis of Phenyl Monomer: 9-BBN (0.5 M in THF, 2.1 equiv.) may beadded dropwise over 30 min to a stirred and cooled (0° C.) solution of1,4-dibromo-2,5-divinylbenzene (8.68 g, 1.0 eqiuv.) in THF (125 mL). Theice bath is removed, and stirring may continue for 10 h. The mixture maybe cooled to 0° C. and quenched by dropwise addition of MeOH. AqueousNaOH (2 M, >1.5 equiv.) and 30% H₂O₂ (>10.0 equiv.) may be poured intothe stirred mixture. Stirring may continue for 2 h, and the mixture maybe extracted with Et₂O. The combined organic extracts may be washed withbrine, dried (Na₂SO₄), and the solvent is evaporated. The crude productmay be purified through column chromatography (silica gel,hexane/EtOAc=3/1). The tetrahydroxy product from the previous step (1.0equiv.) and a catalytic amount of imidazole may be dissolved in anorganic solvent such as DCM. Tert-butyldimethylsilyl chloride (>4.0equiv.) may be added in one portion to the reaction, and the mixture maybe stirred at room temperature until completion. The reaction may bewashed with water, brine, and the organic layer may be dried over MgSO₄.The solvents are removed in vacuo, and the crude product may be purifiedvia recrystallization, column chromatography or by other techniques.

With respect to the tetrazine monomer, the second set of chemicalreactions illustrates that the tetrazine monomer is synthesized byborolyation from commercially available 1,2-dichlorotetrazine or1,2-dibromometrazine (synthesized in one step from commerciallyavailable 3,6-dihydrazinyl-1,2,4,5-tetrazine and dibromocyanuric acid).

Prophetic Example: Synthesis of Tetrazine Monomer

To a solution of dibromo or dichlorotetrazine (1.0 eqiuv.) in DMF isadded potassium acetate (3.0 equiv.), bis(pinacolato)diboron (>1.5equiv.), and PdCl₂dppf (5 mol %). The reaction mixture may be stirred at110° C. until completion. Brine (5 mL) is added and EtOAc (10 mL). Thelayers are separated, and the organic layer may be dried, filtered, andconcentrated in vacuo.

Referring to FIG. 4, a chemical reaction diagram 400 illustrates anexample of a process of forming the tetrazine-phenylene copolymerdepicted in FIG. 1. FIG. 4 depicts a second example of a phenyl monomer(e.g., a phenyl boronic ester monomer) and a tetrazine monomer (e.g., adibrominated tetrazine monomer) that may be co-polymerized. The examplephenyl monomer depicted in FIG. 4 may be synthesized according to thereaction scheme illustrated and further described herein with respect toFIG. 5. The tetrazine monomer of FIG. 4 is 1,2-dibromometrazine and maybe synthesized in one step from commercially available3,6-dihydrazinyl-1,2,4,5-tetrazine and dibromocyanuric acid.

The phenyl monomer and tetrazine monomer are polymerized under Suzukicross-coupling conditions to yield a tetrazine-phenylene copolymer. Anillustrative example of Suzuki cross-coupling conditions includes theuse of Pd(PPh₃)₄ as the Pd catalyst, Cs₂CO₃, and water or DME as asolvent. Similar procedures to those described about with respect to thetetrazine-phenylene copolymer of FIG. 2 may be utilized to form thetetrazine-phenylene copolymer depicted in FIG. 4.

Thus, FIG. 4 illustrates an example of a process of forming atetrazine-phenylene copolymer for use in forming the ladder tetrazinepolymers of the present disclosure. The tetrazine moieties allow forfour ladder linkages per molecule as well as more imines per repeatunit, which allows for a more electron deficient polymer, resulting in anarrower band gap that is ideal for n-type materials.

Referring to FIG. 5, a chemical reaction diagram 500 illustrates anexample of a process of forming the phenyl monomer depicted in FIG. 4.FIG. 5 illustrates that the phenyl monomer depicted in FIG. 4 may besynthesized by borolyation of the phenyl monomer depicted in FIGS. 2 and3. Similar reaction conditions to those described above with respect tothe synthesis of the tetrazine monomer of FIG. 3 may be utilized to formthe phenyl monomer depicted in FIG. 5.

Referring to FIG. 6, a flow diagram illustrates an exemplary process 600of forming a ladder tetrazine polymer, according to a particularembodiment. In FIG. 6, a tetrazine monomer and a phenyl monomer may beused to form a tetrazine-phenylene copolymer, which may be used to formthe ladder tetrazine polymer. As illustrated and further describedherein with respect to FIG. 7, in some cases, the ladder tetrazinepolymer(s) of the present disclosure may be used as an n-type materialin an active layer of an OPV device (e.g., as a replacement for afullerene).

In the particular embodiment illustrated in FIG. 6, operationsassociated with formation of a tetrazine-phenylene copolymer areidentified as 602, while operations associated with formation of aladder tetrazine polymer are identified as 604. It will be appreciatedthat the operations shown in FIG. 6 are for illustrative purposes onlyand that the chemical reactions may be performed in alternative orders,at alternative times, by a single entity or by multiple entities, or acombination thereof. As an example, one entity may produce a tetrazinemonomer, and another entity may produce a phenyl monomer, while anotherentity may form a tetrazine-phenylene copolymer from the tetrazinemonomer and the phenyl monomer. Further, alternative or additionalentities may perform operations associated with forming a laddertetrazine polymer from the tetrazine-phenylene copolymer.

The process 600 includes forming a tetrazine-phenylene copolymer from atetrazine monomer and a phenyl monomer, at 602. For example, thetetrazine-phenylene copolymer may correspond to the tetrazine-phenylenecopolymer depicted in FIG. 1, which may be formed from a phenyl monomerand a tetrazine monomer. FIG. 2 illustrates one example of a phenylmonomer and a tetrazine monomer that may be used to form thetetrazine-phenylene copolymer, where the monomers may be formedaccording to the processes described with respect to FIG. 3. FIG. 4illustrates another example of a phenyl monomer and a tetrazine monomerthat may be used to form the tetrazine-phenylene copolymer, where thephenyl monomer may be formed according to the process described hereinwith respect to FIG. 5.

The process 600 includes forming a ladder tetrazine polymer from thetetrazine-phenylene copolymer, at 604. For example, referring to FIG. 1,the tetrazine-phenylene copolymer may be used to form the first laddertetrazine polymer (depicted at the top of FIG. 1) or the second laddertetrazine polymer (depicted at the bottom of FIG. 1).

Thus, FIG. 6 illustrates an example of a process of forming a laddertetrazine polymer from a tetrazine-phenylene copolymer. In some cases,the ladder tetrazine polymers of the present disclosure may be used as acomponent (e.g., an n-type material) of an active layer of an OPV device(as illustrated and further described herein with respect to FIG. 7).

Referring to FIG. 7, a flow diagram illustrates an exemplary process 700of forming an active layer of an OPV device from a blend that includesthe ladder tetrazine polymer(s) of the present disclosure, according toone embodiment. While FIG. 7 depicts an example in which the laddertetrazine polymer(s) of the present disclosure are used as a componentof an OPV device, it will be appreciated that the ladder tetrazinepolymers of the present disclosure may be used in other contexts, suchas organic batteries or organic sensors (among other alternatives).

In the particular embodiment illustrated in FIG. 7, operationsassociated with formation of a blend of materials that includes theladder tetrazine polymer(s) of the present disclosure are identified as702, while operations associated with formation of an active layer of anOPV device from the blend are identified as 704. It will be appreciatedthat the operations shown in FIG. 7 are for illustrative purposes onlyand that the operations may be performed in alternative orders, atalternative times, by a single entity or by multiple entities, or acombination thereof. As an example, one entity may produce the laddertetrazine polymer, another entity (or entities) may produce the othermaterial(s) for the blend, while another entity may mix the materials toform the blend. Further, alternative or additional entities may performoperations associated with forming the active layer of the OPV devicefrom the blend.

The process 700 includes forming a blend that includes a laddertetrazine polymer (or multiple ladder tetrazine polymers) and one ormore other materials, at 702. The process 700 also includes forming anactive layer of an OPV device from the blend, at 704. For example, thefirst ladder tetrazine polymer and/or the second ladder tetrazinepolymer depicted in FIG. 1 may be mixed with one or more other materialsto form a blend. As an example, the ladder tetrazine polymer(s) of thepresent disclosure may represent an n-type material that may be used toreplace PCBM. In this case, the ladder tetrazine polymer(s) may be mixedwith one or more p-type materials that are suitable for use in an activelayer of an OPV device.

As described further herein, the ladder tetrazine polymers of thepresent disclosure have desirable solubility characteristics, allowingfor processing by common polar solvents, such as chloroform, THF, andDMF. Further, the high ionic content of the ladder tetrazine polymers ofthe present disclosure may allow for aqueous processing. Tetrazinemoieties allow for four ladder linkages per molecule as well as moreimines per repeat unit. The enhanced number of imines allows for a moreelectron deficient polymer, resulting in a narrower band gap that isideal for n-type materials.

It will be understood from the foregoing description that modificationsand changes may be made in various embodiments of the present inventionwithout departing from its true spirit. The descriptions in thisspecification are for purposes of illustration only and are not to beconstrued in a limiting sense. The scope of the present invention islimited only by the language of the following claims.

What is claimed is:
 1. An organic battery comprising an activecomponent, the active component that includes a ladder tetrazinepolymer, the ladder tetrazine polymer comprising a substituted benzenering that includes two tetrazine groups arranged in a para-substitutionpattern, each tetrazine group including two iminium cations.
 2. Theorganic battery of claim 1, wherein the ladder tetrazine polymerincludes alkyl-functionalized anions.
 3. The organic battery of claim 2,wherein the alkyl-functionalized anions include linear alkyl chains. 4.The organic battery of claim 3, wherein the linear alkyl chains have achain length in a range of one carbon atom (C1) to twenty carbon atoms(C20).
 5. The organic battery of claim 2, wherein thealkyl-functionalized anions include branched alkyl chains.
 6. Theorganic battery of claim 5, wherein the branched alkyl chains have abranching point at a first carbon atom (C1) or at a second carbon atom(C2).
 7. The organic battery of claim 5, wherein the branched alkylchains correspond to 3,7-dimethyloctyl chains.
 8. The organic battery ofclaim 1, wherein the ladder tetrazine polymer includes chloride anions.